Thermal oracuit-controlleb



NAGAKATA NlFn AND NEGASUMI NISHI.

THERMAL CIRCUIT CONTROLL'ER.

APPLICATION FlLED JAN. 11, 1919.

1 34 5 1 4 Patented Aug. 3, 1920.

2 SHEETS-*SHEET I.

J l I I 35 lummtoz 7 4 "a; 6 3 l130 .A ZyakQZa/NZISZJ Nc gagumv Nwhv ww MU NAGAKATA NlSHI AND NEGASU MI NISHI. THERMAL CIRCUIT CONTROLLER.

APPLICATION FILED JAN. 11. 1919.

.U NlTEDeSTATES PATENT orr es.

w om-re msnr Am) NAGASUMI msnr, or BERKELEY, CALIFORNIA.

THERMAL CIRCUIT-CONTROLLER.

i Specification of Letters Patent. A g 3 1920 iirppncaaoa filed January 11, 1919. Serial No. 270,728.

To all whom it ma: concern: I

Be it known t at we, NAGAKATA NISHI and NAGASUMI NIsHI, subjects of the Em-- peror of Japan, residing at Berkeley, in the county of Alameda and State of California, have invented certain new and usefulv Improvements in Thermal Oircuit-Oontrollers, of which the following is a spec1fica-' tion.

Our invention is an automatically controlled electric lron, comprising means whereby the electric current may be automatically shut off when the heat of the iron rises to a predetermined degree and automatically turned on when the iron cools slightly below said degree.

In this specification and the annexed drawings, we disclose our invention in the,

form which we consider the best, but we do not limit ourinvention to such form because it may be embodied in otherforms, and. it-

is to be understood that in and by the claims following the description herein we intend.

p the irontaken on line 3-3 of Fig. 4E.

Fig. 4; is a horizontal section of the iron taken on line 4.4 of Fig. 1. i

Fig. 5 is a bottom plan view of theheating element. I

.F'g. 6 is a topplan of the heating element.

Fig. 7 is a sectional view showing the coupling'member 77 and the lower part of bar 70 andthe screw securing said member to said bar.

Fig. 8 is a sectional view showing the coupling member 7 6, the upper end oi stud 60 and plug-64 for mounting the member 76 on said stud.

Fig. 9 is a detailsectional view taken on an enlarged scale taken on line 9-9 oi Fig. 2..

In the drawings, 1 indicates a base which is formed with a lower ironing surface 2. A pair of upstanding studs 3 and 4 are screwed into the top of base 1 on the central axis thereof.- On top of the base 1 rests a plate of mica 5, the studs 3 and 4 extending the bracket in position.

throu h apertures 6 and 7 in said plate. On themlca plate 5 rests a heating element 10 which includes a "pair of flat heating coils 11 and 12 wound on mica plates 13 and 14, a.

plate ofmica 15jciovi'erin said heating coils, and'a pair of metal con] uctor plates 16 and 17 resting on'plate 15- directly over said heatinglcoils; the studs-3 and 4-l projecting through apertures "IS-and 19: in plate 15 and between theheati'ng'coils .12 and 13 and between the plates 16and'17. The heating coils 12 and 13and'pl'ates16 and 17 are secured upon the plate"15 by rivets 20 and 21, the rivet 20 holding the heating coil 11 and plate 16 to the plate 15, and the rivet 21 holding heating coil 13 andplate 17 toplate 15; A plate 23 of mica rests upon the plates 16, and 17016 the heating element 10, the studs, 3' and 4 extending through apertures 24am 25 in the plate. A thick metal plate 26, provided with apertures 27 and 28 rests uponthe mica plate 23, the studs 2 and 3 extendingct-hrough said apertures. Nuts 29 and 30 screw onthe upper ends of the stud bases'agains't the top plate 26 and clamp the heating element 10 and mica plates 5 and 23 betweenthe plate 26 and base 1. The upper portions of the studs 3 and 4 are reduced and threaded. A cover provided with apertures 3 6 and 37.fits upon the base 1 over the heating element 10 and plates 5,

23 and 26 and nuts 29 and 30, the reduced upper portions'of studs 3 and 1 extending through said apertures 36 and 37. Nuts 38 and 39 screw on the reduced portions of studs 3and 41 against the top of the cover 35 and clamp said cover in position on the base 1 and over the parts as described. A handle bracket 410 provided with apertures 41 and 42 rests upon nuts 38 and 39, the studs 3 and 1 projecting through said apertures, and nuts 13 and 44 screw on the ends of said studs against the bracket and clamp A handle 45 is secured to the upper ends of bracket 40.

On the rear of the iron is mounted a thermostat for controlling the current in the heating coils 11 and 12. Said thermostat includes a body 51, of porcelain or other suitable insulation, formed in twovertical members 52 and 53, the lower end of p which body rests in a recess 54; in the rear part of the cover 35 and the forward member 52 of said body rests against the rear of which rests against said rear bracket member. :1 bolt 56 extends through the rear wall 0t casing 55, body members 53 and 52, i'ront wall of said casing and through the rear member of handle bracket 10. and a nut 57 screws on the forward end or said bolt against said bracket member whereby said casing and body 51 are held in position at the rear of the iron as described and as shown in the drawing. Studs 60, 61 and 62 of copper or other suitable material 01 the pro er coeilicient of expan sion, heat conductivity, melting point and specific heat are welded or otherwise secured to the top of the base 1 at the rear thereof and project upwardly through apertures 58, 58 and 59 in the bottom of recess 54 into space 63 within the body 51. The studs 60, 61 and 62 are of ditterent heights, the stud 60 being the least in height, the stud 61 next in height and the stud 62 the highest. A plug 6 1 of suitable insulation is fitted in the top of stud 60 and projects upwardly therefrom. 41 bar of porcelain or other suitable insulation located within space 63 in the body 51 is coupled by coupling to the upper end of stud 60 which coupling includes two interlocking members 76 and 77 the member 76 being secured on the upper end of plug 6% and the member '77 being secured to the lower end 01": bar 70 by means of screw 78. The members 76 and 77 are formed with interlocking lugs 79 and 80 which interlock to couple the lower end of bar '70 to the upper end of stud 60. The bar 70 is provided with a conduit 81 extending from the inner end of screw 78 to the upper end of the bar through which con duit extends a conductor 82 which engages the screw 73 at its lower end and a screw 83 at its upper end which screws into the upper end of the conduit. A. nut 81 screws on the upper end of screw 83 against the lower coil of a spring 85 and connects the lower 1d of said spring to screw 83. The spring 2 tits in space 86 in body 51 and bears at its lower end against the top of bar 70 and at its upper end against a metal head 87 fixed in a socket 88 in said body.

A plug 89 of insulation is fitted in the top or stud 62 and acollar 90 is secured on the upper end of said plug which carries a platinum contact 91. A horizontal arm 92 oi? porcelain or other suitable material is pivoted at 71 within the space 63 in the body 51 and has a platinum contact 93 on its lower edge at its swinging end adapted to engage contact 91. A screw 9% extends upwardly through contact 93 and the swinging end of arm 92 and a nut 95 screws on of arm 92 while its upper end bears against a metal head 98 mounted in a socket 99 in the body 51, thus forcing the swinging end of: arm 92 downward and the contact 93 into contact-"with contact 91. A wire 100 connects to head 87 and a wire 101 connects to head 98, which wires lead through a space 102 in body 51 and are twisted together and lead through an opening 103 in the top of casing 55. The upper end of the rear member of bracket 40 has a rear extension 104: which extends rearwardly at a slight downward inclination and then downward. The upper part of the extension 10& has an aperture 105 through which the twisted wires 100 and 101 extend. The wires 100 and 101 are clamped to the lower end of extension 104 on the inside thereof by a clamp 106 which comprises a clamp member 107 and a bolt 10S and nut 109, said bolt extending through the lower end of extension 104- and between wires'100 and 101 and through an aperture in said clamp member and said nut screwing on the inner end of said bolt against said clamp member and drawing said clamp member against said extension and against said wires. A spring 110 surrounds the wires 100 and 101 above the extension 10 1 and rests at its lower end upon said eff-31131011 68161 spring preventing bending and breaking of the wires.

The stud 61 has an upstanding threaded extension 111 on which screws a threaded sleeve 112 which constitutes an adjustable control element for engaging and raising arm 92 and breaking electrical circuit of the iron between contacts 91 and 93. The sleeve 112 has a conical upper end 113 for accurate engagement with the under side of arm 92. A stud 114 projects radially from the lower end of sleeve 112 on which stud an indicator 115 telescopes. A plate 116 is secured by screws 117 to the rear wall of the cover 35 from the upper edge of which plate a dial 118 extends horizontally in a rearward direction on the face of which dial at its outer edge is a scale 119 indicating degrees of heat. The plate 116 is provided with a horizontal slot 120 and the dial 118 is provided with an arcuate slot 121 concentric with the axis of the sleeve 112 through which slots extends the indicater 115 the point 125 of which rests over the scale 119.

Insulators and 131 are secured respectively to the forward face of studs 60 and 62 by screws 132. Said insulators are provided with vertical grooves 133 and 134: through which respectively extend wires 135 and 136. the wire 135 being secured at one end to member 7 6 and at its other end to an upstanding lug 137 on the rear end of plate 16 by screw 138, and the wire 136 being secured at one end to metal collar 90 and at its other end to upstanding lug 139 rear end of coils 11 and. 12 extendthrough the mica plate 15 and connect to plates 16 and 17 near lugs 137 and-139. The forward end'of the conductor of. the coil 11 extends onto the forward end of plate 14 and winds thereon forming coil 12.. I

Byswinging the indicator 115 over the scale 119 to the mark indicating the desired degree of heat, the sleeve 112' is turned and moved up or down on the threaded extension or shank 111 and the thermostat 50 set to shut off the current when the heat of the coils 11 and 12 reaches said predeten mined degree. As the heat of the iron rises the studs 60, 61 and 62 expand upwardl until the predetermined degree is reache whereupon the point of sleeve 112, engaging arm 92, swings said arm upwardly on its pivot and disengages contacts 91 and 93 and breaks the circuit including heating coils 11 and 12. The iron then cools and the studs 60, 61 and 62 contract untll the point of thesleeve 112 is lowered sufficiently to enable the arm 92 to swing. down under the influence of spring 96 tobring contacts 91 and 93 into contact to reestablish the circuit and heat the iron.

The relative heights of the studs 60, 61' and 62 effect a corresponding expansion and' mined degree before the stud 61 can raise' the sleeve 112 and cause arm 92 to swing and break the circuit.

WVhen the iron cools, after the current is shut off at a predetermined degree of heat, the stud 60, being the lowest in height, expands less than the studs 61 and 62 and maintains the pivot 71 elevated, so that the end of arm 92 has a shorter distance than it would otherwise have, to swing down in order to bring the contacts 91 and 93 into contact and reestablishthe circuit, thus enabling the arm to swing andmake contact, as soon as the stud 61 contracts sufficiently and disengages sleeve 112 from said arm, as soon as the stud 62 has contracted only slightly. This operation makes it unnecessary for the studs 61 and 62 to contract to 7 zero before reestablishing the circuit.

The relative lengths of the studs 61, 62 and 63 andthe distances at which they are spaced apart'are determined by careful experiment, in order to give the arm 92 the proper movement.

Having described our claim: a

1. In an electric iron, a thermostat including three expansible and contractible studs of different lengths mounted on the base of the iron, a bar connected to the shortest stud but insulated therefrom, an arm pivoted on said bar, a contact on said arm, a contact mounted on the longest stud,

invention, we

but insulated therefrom, to be engaged by the contact on said arm, said contacts being connected in series in the iron circuit,

means on the stud of intermediate length for engagingthe' arm to break contact between said contacts when said intermediate stud has expanded under a predetermined degree of heat. 1

2. In an electric iron, a thermostat including three expansible and oontractible studs of different lengths mounted on the base of the iron, a bar connected to the shortest stud but insulated therefrom, an arm pivoted on said bar, a contact on said arm, a

contact mounted on the longest stud, but,

3. In an electric iron, a thermostat including three expansible and contractible studs of different lengths mounted on the base of the iron, a bar connected to the shortest stud, an arm pivoted to said bar, a contact on said arm, a contact mounted on the longest stud, said contacts being included in the iron circuit, means on the stud of intermediate length for engaging the arm to break contact between said contacts when said intermediate stud has expanded under a predetermined degree of said bar, and a spring bearing against the swinging end of said arm. I

4. In an electric iron, a thermostat including three expansible and contractible studs of different lengths mounted on the base of the iron and projecting through the cover of said base, a bar detachably connected to the shortest stud and permit ting removal and replacement of the cover on the base, an arm pivoted to said bar, a contact on said arm, a contact mounted on the longest stud but insulated therefrom, said contacts being included in the iron circuit, means on the stud of intermediate length for engaging said arm to break contact between said contacts when said intermediate stud has expanded under a predetermined degree of heat.

5. In an electric iron, a thermostat inmeans on theother stud for engaging said arm and breaking said contacts when the studs have expanded under a predetermined degree of heat.

6. In an electric iron, a thermostat including an expansible and contractible stud mounted on the base of the iron, an arm, a contact on said arm, a contact to be engaged by said arm contact, said contacts being included in the iron circuit, a threaded member on said stud, a sleeve screwing on said threaded member for engaging said arm and breaking said contacts when the stud has expanded under a predetermined degree of heat, an indicator on said sleeve, and a dial with heat graduations to which said indicator points to indicate the degree of heat at which said sleeve is set to engage said arm to break said contacts.

7. In an electric iron, three expansible and contractible studs oi difi'erent lengths mounted on the base of the iron, a cover. for said base formed with a recess, one wall of which being open to receive said studs, a hollow insulating body resting in said recess over said studs, a bar connected to the shortest stud within said body, an arm pivoted to said bar, a contact on said bar, a contact mounted on the longest stud, said contacts being included in the iron circuit, means on the stud of intermediate length for engaging said arm to break said contacts when the iron has reached a predetermined degree of heat, and means for securing said on the iron.

8. In an electric iron, three eXp-ansible and contractible studs mounted on the base of the iron, a cover for said basetormed with recess, one wall f which being open to receive said studs, a hollow insulating body resting in said recess, over said studs, a bar connected to the shortest stud within said body, an arm pivoted to said bar, a contact on said arm, a contact mounted on the longest stud, said contacts being included in the iron circuit, means on the stud of intermediate length for engaging said arm to break said contacts when said intermediate stud has expanded under a predetermined degree of heat, said body being formed in two sections, and a bolt extending through said sections and through the handle bracket of the iron and a nut on one end of said bolt for holding said body on the iron 9. In an electric iron, an expansible and contractible stud mounted on the base of the iron, a contact mounted on said stud, an arm. a contact on said arm for engaing said other contact to close the iron circuit, and means for automatically swinging said arm and breaking said contacts when the iron reaches a predetermined degree of heat.

10. In an electric iron, a thermostat ineluding an expansible and contractible stud, mounted on the base of the iron, an arm, a contact on said arm, a contact engaged by said arm contact, said contacts being included in the iron circuit, a threaded member on said stud, and a sleeve screwing on said threaded member for engaging said arm and breaking said contacts when the stud has expanded under a degree of heat determined by said sleeve and threaded stud member.

11. In an electric iron, three studs mounted on the base of the iron, an arm pivot-ally mounted on one of said studs, a contact on one of the other studs, a contact on said arm for engaging the contact on said stud, the third stud being expansible and contractible, and means 011 said expansible and contractible stud for engaging said arm and disengaging said contacts when said stud has expanded under a predetermined degree of heat.

12. In. an electric iron, three studs mounted on the base of the iron, an arm pivoted on one of said studs, a contact on another stud, a contact on said arm for engaging the contact on said stud, the third stud being expansible and contractible, a threaded part on said expansible and contractible stud, and a threaded sleeve screwed on said threaded part of said expansible and contractible stud for engaging said arm and breaking said contact under a predetermined degree of heat.

13. In an electric iron, three studs mounted on the base of the iron, a'detachable cover for said base through which said studs extend, an arm pivotally mounted on one of said studs, a contact on another stud, a contact on said arm for engaging the contact on said stud, the third stud being expansible and contractible, means on said expansible and contractible stud for engaging said arm and disengaging said contacts when the iron reaches a predetermined de gree of heat, and a hollow insulated body telescoped over said studs.

14. In an electric iron, three studs mounted on the base of the iron, an arm pivotally mounted on one of said studs, a contact on said arm, a contact on another stud engaged by said arm contact, a spring bearing upon said arm to maintain said contacts in engagement, the third stud be ing expansible and cont 'actible, and means on said expansible and contractible stud for engaging said arm and disengaging said contacts when the iron reaches a predetermined degree of heat.

In testimony whereof we affix our signatures.

NAGAKATA NISHI. NAGASUh II NISHI. 

